Method for coating pipe

ABSTRACT

A METHOD AND APPARATUS FOR COATING A PAIR OF PIPE SECTIONS UTILIZES SPACED, PARALLEL, TRACK VEHICLES FOR MOVING THE SECTIONS ON OPPOSITE SIDES OF A CENTRAL COATING STATION. COATING MATERIAL IS ALTERNATELY SUPPLIED FROM THE STATION TO TWO APPLICATORS, WHICH ARE LOCATED ADJACENT AND PERPENDICULAR TO THE RESPECTIVE TRACKS, BY A REVERSIBLE FEEDER BELT. MOVEMENT OF THE SECTIONS IS FORWARD TO THE COATING STATION AND THEN BACKWARD AWAY FROM THE STATION. THE PIPE SECTIONS ARE SPACED APART IN THEIR DIRECTIONS OF TRAVEL SO THAT THEIR PATHS ARE 180* OUT OF PHASE AND ONE OF THE SECTIONS IS AT THE FOWARD END OF ITS PATH OF TRAVEL WHILE THE OTHER IS AT THE BACKWARD END OF ITS PATH OF TRAVEL. THUS, ONE SECTION CAB BE SUBJECTED TO THE COATING STEP WHILE THE OTHER SECTION IS BEING REMOVED FROM THE TRACK VEHICLE.   D R A W I N G

July 4, 1972 HARRls ETAL 3,674,546

Filed Jan. 6, 1971 2 Sheets-Sheet 1 I l l l IITT I LI 2 Sheets-Sheet 2 R. J. HARRIS E 'AL METHOD FOR COATING PIPE July 4, 1972 Filed Jan.

INVENTORS. Roberf J Harris n Irvin J. Leg BY ATTORNEY United States Patent U.S. Cl. 117-94 7 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for coating a pair of pipe sections utilizes spaced, parallel, track vehicles for moving the sections on opposite sides of a central coating station. Coating material is alternately supplied from the station to two applicators, which are located adjacent and perpendicular to the respective tracks, by a reversible feeder belt. Movement of the sections is forward to the coating station and then backward away from the station. The pipe sections are spaced apart in their directions of travel so that their paths are 180 out of phase and one of the sections is at the forward end of its path of travel while the other is at the backward end of its path of travel. Thus, one section can be subjected to the coating step while the other section is being removed from the track vehicle.

This invention relates to a coating apparatus and method, and more particularly, to a method and apparatus for expediting the coating of pipe sections.

It has long been the practice to provide a protective coating for pipe sections to be buried in the ground and also for pipe lines placed in marine applications. The coating is usually either a concrete aggregate material or a mastic material with a bituminous asphaltic base.

While several methods of coating the pipe sections have been utilized, one of the most desirable from a cost standpoint makes use of a rapidly rotating brush to impinge the coating material onto the pipe sections as the latter move relative to the rotating brush. This method, which was initially limited to concrete coatings, has recently been successfully extended to mastic coatings.

The primary object of the present invention is to provide a method and apparatus for coating pipe sections which includes throwing, spraying, or impinging the coating onto the sections and wherein the coating time per unit is substantially reduced by using spaced, parallel coating lanes on opposite sides of a central coating prep aration station.

An important object of this invention is also to minimize the equipment required for the coating of pipe sections by utilizing a central supply facility and pug mill for supplying duel applicators located on opposite sides of the pug mill, to permit handling of a pair of pipe sections with less than twice the equipment previously required to coat a single pipe section.

Still another object of the invention is a method and apparatus for coating a pair of pipe sections wherein dual applicators are utilized and a reversible feeder belt allows both applicators to be applied from a single source by simply reversing the direction of travel of the belt.

These and other important objects of the invention will be further explained or will become apparent from the following specification and claims.

In the drawings:

FIG. 1 is a top plan view of the coating apparatus of the present invention;

FIG. 2 is an enlarged cross-sectional view of the apparatus taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged front elevational view of one of the control gates which maintain a uniform level of the ice coating material along the feeder belt, with portions being broken away for purposes of illustration; and

FIG. 4 is a partial side elevational view of the apparatus shown in FIG. 3.

Referring initially to FIG. 1, a pipe coating plant constructed according to the present invention is designated generally by the numeral 10 and includes a central coating station 12 from which coating material is delivered to a pair of identical coating applicators 14 and 16. A pair of spaced, parallel tracks 18 and 20 are disposed perpendicular and adjacent to the respective applicators 14 and 16. The tracks 18 and 20 are longitudinally extending past a pair of loading stations where pipe sections 22 and 22' are supported upon two sets of pipe racks 24 and 26 respectively.

A pair of pipe-coating vehicles 28 and 30 are each comprised of a pair of individual coating buggies 32. The pipe sections 22 and 22 are moved from the supporting racks 24 and 26 and onto the vehicles 28 nd 30 by loading jacks 34 and 36 respectively.

The coating station 12 includes a storage area which encloses a quantity of sand 38 used in preparing the concrete coating, and a pair of tanks 40 store a supply of cement which is fed through a conveyor 42 and a chute 44 to a pug mill 46. A pair of hoppers 48 provide structure for introducing the sand 38 into the pug mill 46 through the chute 44. Any of the concrete coating mate rial which does not adhere to the pipe section being coated drops into areas 50 and 52 beneath the tracks 18 and 20 respectively from which it is conveyed to the pug mill 46 by conveyors 54 and 56 respectively.

Referring now to FIGS. 2-4, wherein further details of the coating station 12 are shown along with details of the two applicators 14 and 16. The pug mill 46 includes a hopper 58 at the forward end thereof for delivering the concrete coating material onto a reversible feeder belt 60. The feeder belt 60 is supported by a pair of rollers 62 and 64 at opposite ends with each of the rollers having its shaft journaled in appropriate bearing housings 66 and 68. The bearing housings 66 and 68 are in turn supported by a frame 70 which is rigid with a first pair of C- channels 72 which are welded or otherwise rigidly secured to a second pair of C-channels 74. A plurality of upright standards 76 support the entire assembly of the belt 60 and rollers 62 and 64, along with the hopper 58 upon a platform 78. The belt 60 is driven by a reversible motor 80 through a pulley and belt assembly 82.

At each side of the hopper 58 a control gate designated generally by the numeral 84 is located for assuring that the coating material deposited upon the belt 60 is uniformly distributed. Each of the gates 84 comprises an upright support rod 86 which is operably coupled with a handle 88 for moving the gate 84 in a vertical plane. At the end of the rod 86 opposite the handle 88 a generally planar, vertically disposed gate member 90 extends transversely of the belt 60 in vertically spaced relationship to the latter. Extending rearwardly from the member 90 are a pair of outwardly flared vanes 92 which converge toward the member 90 in a V-shaped configuration.

It is also to be noted from FIG. 3 that a pair of legs 94 which depend from the hopper 58 are configured to form a slot for receiving the belt 60 and also include an inclined surface 96 for directing the coating material onto the belt 60. A roller 98 at one side of the belt 60 restricts lateral movement of the latter and a similar roller is normally provided at the opposite side to restrict lateral movement of the belt in the opposite direction.

A pair of conveyor belts 100 and 102 which are driven by motors 104 and 106 respectively, transport the coating material from the feeder belt 60 to the respective applicators 14 and 16. The delivery belts 100 and 102 3 are supported by rollers 108, 110, 112 and 114 disposed to assure direct fore and aft alignment between the belts and the respective applicators.

As each of the applicators 14 and 16 are identical, only one of the same will be described in detail. Each of the applicators, such as 14, acts as an impinger and is comprised of a brush 116 and a belt 118. Both the brush 116 and the belt 118 are driven at relatively high speeds by an appropriate drive mechanism (not shown).

A pair of operators platforms 120 are disposed upon upright supports 124 and 126 respectively which are in turn mounted upon platforms 128 and 130. From the platforms 120 and 122 the operator is in position to move the control gates 132 and 134 which are identical in construction to control gate 84 previously described.

As will be noted from viewing the coating buggy 32 which is visible in the far lefthand corner of FIG. 2, each of the buggies is provided with a pair of rollers 136 upon which a pine section 22 rests during the coating operation. The rollers 136 are rotated by an appropriate prime mover (not shown). This allows the section 22 to be rotated to permit its entire exterior surface to be coated as the coating vehicle moves the pipe section past one of the coating applicators.

In operation, the vehicles 28 and 30 are first loaded with the pipe sections 22 and 22 and then moved forwardly along the tracks 18 and 20 to the applicators 14 and 16. It is desirable to space the vehicles 28 and 30 apart in their directions of travel so that their paths of travel are approximately 180 out of phase with each other. In this manner, one of a pair of pipe sections being coated is at the forward end of its path of travel and adjacent the applicator 14 while the other section which has been previously coated is at the backward end of its path of travel and adjacent a load out area 138. Coating material is directed to either the applicator 14 or the applicator 16 depending upon the direction of rotation of the feeder belt 60. Movement of the feeder belt 60 in one direction delivers coating material to the belt 100 and applicator 14 while movement in the other direction delivers coating material to the belt 102 and applicator 16. As the coating material drops onto the belt 118 which is moving at a high rate of speed, it is flung onto a pipe section 22 by the action of the rapidly rotating brush 116. The latter also serves to assure that the coating material remains sufi'iciently particulate to provide a compactable, adherent mass for contact with the outer surface of the pipe section. It is to be understood, of course, that in applying certain coatings it is necessary to include a layer of reinforcing material (not shown) which is wrapped around the pipe section simultaneously with the coating operation. The control gates 88, 132 and 134 are raised or lowered to assure a uniform and evenly distributed layer of coating material upon the belts 60, 100 and 102.

It is to be understood that in normal operation the motor 80 will be timed to reverse its direction periodically to deliver coating material to either the belt 100 or the belt 102 depending upon which of the coating vehicles 28 or 30 is in alignment with an applicator 14 or 16. It will be appreciated that by utilizing the coating method of the present invention, which includes providing a central coating station from which a coating material is delivered, moving a pair of pipe sections forward and backward 180 out of phase along spaced, parallel paths of travel on opposite sides of the station, and alternately impinging the coating material onto the pipe sections as the latter are rotated and brought into alignment with the coating station, a pair of pipe sections can be coated in only slightly greater time than has been previously required for coating a single pipe section. This is accomplished with less than twice the equipment and labor that has previously been required for coating a single pipe section.

It will, of course, be apparent to those skilled in this art that the construction might be varied somewhat without departing from the principles of this invention. For example, a single belt could extend between applicators 14 and 16. This single belt would be reversibly driven to provide the feature of alternate directions of travel for the coating material to the respective applicators. Such construction, while capable of accomplishing most of the objects of the invention, would also permit elimination of the reversible belt 60. On the other hand, this construction is believed less efficient in overall operation because of the necessity for repeatedly reversing the direction of a single, relatively long belt rather than the substantially shorter belt 60 utilized in applicants presently preferred construction.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A method of coating a pair of pipe sections comprising the steps of:

providing a coating station from which a coating material is delivered;

moving the pipe sections to be coated along spaced paths of travel on opposite sides of said station, said sections being spaced from each other in their directions of travel so as to alternately bring said sections into alignment with said station; and alternately directing the coating material in opposite directions onto the pipe sections as the latter move into alignment with the coating station.

2. A method as set forth in claim 1, wherein said moving step includes moving said sections along parallel paths of travel which paths are perpendicular to said coating station.

3. A method as set forth in claim 1, wherein said moving step includes moving said sections forward to said coating station and backward away from said station along said paths of travel and removing said sections from said paths after said backward movement is completed.

4. A method as set forth in claim 3, wherein is included the step of spacing said sections so that their paths of travel are out of phase whereby one of said sections is at the forward end of its path of travel when the other of said sections is at the backward end of its path of travel.

5. A method as set forth in claim 3, wherein said directing step includes impinging said coating on said pipe sections.

6. A method as set forth in claim 5, wherein is included the step of rotating said pipe sections during impinging of said coating.

7. A method as set forth in claim 5, wherein is included the step of collecting any of said material not adhering to said sections and returning the same to said coating station.

References Cited UNITED STATES PATENTS 2,696,353 12/1954 Vessels 1l794 X 3,526,525 9/1970 Verssor et al. 117-94 X EDWARD G. WHITBY, Primary Examiner U.S. Cl. X.R.

117-168, 169 A; 118-313, 321, Dig. 11, Dig. l6 

